The Molecular Genetics Core Laboratory (MGCL) is a shared resource facility that will provide expertise in clinical and molecular human genetics for collaborations and service to the investigators participating in the projects of the Interdisciplinary Basic Research in Dermatology Program. The specific aims of the core are: 1. To provide clinical diagnosis and collection of tissue samples of patients and families affected with inherited skin disorders of keratinization or adhesion. 2. To provide a DNA sequencing service. 3. To construct and bank immortalized lymphoblastoid cell lines of probands and their families affected with inherited skin disorders. 4. To sequence the candidate gene, PPP2C which encodes the protein phosphatase 2A catalytic subunit, of selected harlequin ichthyosis patients for mutation.